Limiting amino acids for growing Holstein steers limit-fed soybean hull-based diets.

2000 ◽  
Vol 78 (7) ◽  
pp. 1997 ◽  
Author(s):  
R H Greenwood ◽  
E C Titgemeyer
1972 ◽  
Vol 27 (3) ◽  
pp. 475-481 ◽  
Author(s):  
Z. Dvořák

1. The amounts of available cystine and tyrosine in the protein of different animal tissues showed a close correlation with the level of hydroxyproline, and may be estimated from hydroxyproline values by regression equations.2. Estimates of ‘chemical score’ have been calculated from the content of hydroxyproline determined in a series of samples for which net protein utilization (NPU) for rats had also been determined. Chemical scores calculated as percentages of the total ‘essential+semiessential’ amino acid content of each material correlated closely with NPU, whereas scores calculated as percentages of total amino acids did not. ‘Methionine+cystine’ were calculated to be first limiting amino acids in every sample.


Nutrients ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 520 ◽  
Author(s):  
Anne Daly ◽  
Sharon Evans ◽  
Satnam Chahal ◽  
Saikat Santra ◽  
Alex Pinto ◽  
...  

Introduction: In phenylketonuria (PKU), evidence suggests that casein glycomacropeptide supplemented with rate-limiting amino acids (CGMP-AA) is associated with better protein utilisation and less blood phenylalanine (Phe) variability. Aim: To study the impact of CGMP-AA on blood Phe variability using 3 different dietary regimens in children with PKU. Methods: This was a 6-week randomised controlled cross-over study comparing CGMP-AA vs. Phe-free l-amino acids (l-AA) assessing blood Phe and tyrosine (Tyr) variability over 24 h in 19 children (7 boys) with PKU, with a median age of 10 years (6–16). Subjects were randomised to 3 dietary regimens: (1) R1, CGMP-AA and usual dietary Phe (CGMP + Phe); (2) R2, CGMP-AA − Phe content of CGMP-AA from usual diet (CGMP − Phe); and (3) R3, l-AA and usual dietary Phe. Each regimen was administered for 14 days. Over the last 48 h on days 13 and 14, blood spots were collected every 4 h at 08 h, 12 h, 16 h, 20 h, 24 h, and 04 h. Isocaloric intake and the same meal plan and protein substitute dosage at standardised times were maintained when blood spots were collected. Results: Eighteen children completed the study. Median Phe concentrations over 24 h for each group were (range) R1, 290 (30–580), R2, 220 (10–670), R3, 165 (10–640) μmol/L. R1 vs. R2 and R1 vs. R3 p < 0.0001; R2 vs. R3 p = 0.0009. There was a significant difference in median Phe at each time point between R1 vs. R2, p = 0.0027 and R1 vs. R3, p < 0.0001, but not between any time points for R2 vs. R3. Tyr was significantly higher in both R1 and R2 [70 (20–240 μmol/L] compared to R3 [60 (10–200) μmol/L]. In children < 12 years, blood Phe remained in the target range (120–360 μmol/L), over 24 h, for 75% of the time in R1, 72% in R2 and 64% in R3; for children aged ≥ 12 years, blood Phe was in target range (120–600 μmol/L) in R1 and R2 for 100% of the time, but 64% in R3. Conclusions: The residual Phe in CGMP-AA increased blood Phe concentration in children. CGMP-AA appears to give less blood Phe variability compared to l-AA, but this effect may be masked by the increased blood Phe concentrations associated with its Phe contribution. Reducing dietary Phe intake to compensate for CGMP-AA Phe content may help.


1990 ◽  
Vol 38 (3B) ◽  
pp. 609-622
Author(s):  
N.P. Lenis ◽  
J.T.M. van Diepen

Individual and group housed crossbred pigs 45 to 105 kg and 65 to 95 kg in experiments 1 and 2, respectively, were given basal diets with L-threonine 0.6, 1.2 and 1.8 g/kg. Positive and negative control diets contained total threonine 5.7 and 4.5 g/kg, respectively. To prevent other amino acids being limiting, the negative control diet was supplemented with lysine, methionine, tryptophan, isoleucine, histidine and valine. The positive control diet was supplemented with lysine and methionine. The requirement for total threonine of growing-finishing pigs for maximum growth performance was about 5.6 g/kg in a diet containing net energy 9.4 MJ/kg. This figure corresponds with about 4.7 g/kg apparent faecal digestible threonine and 4.3 apparent ileal digestible threonine. There was no difference between the growing and the finishing pigs. The requirement for ileal digestible threonine, relative to ileal digestible lysine requirement, was about 64%. It is concluded that dietary protein can be reduced by 2 percentage units without any adverse effect on growth performance, if limiting amino acids are sufficiently supplemented. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2018 ◽  
Vol 74 (10) ◽  
pp. 5971-2018 ◽  
Author(s):  
PRZEMYSŁAW KNYSZ ◽  
MICHAŁ GONDEK ◽  
RENATA PYZ-ŁUKASIK ◽  
MONIKA ZIOMEK ◽  
ŁUKASZ DROZD ◽  
...  

The aim of the study was to determine the variability in the chemical composition and nutritive value parameters of smoked and unsmoked short-ripened rennet cheeses and unsmoked long-ripened rennet cheeses produced by traditional methods. The raw material for the production of short-ripened cheeses was pasteurized cows’ milk obtained from a dairy, whereas the long-ripened cheeses were manufactured from raw cows’ milk obtained from the producer’s farm. All three varieties of cheese examined were produced with commercial dairy starter cultures. The material for the study was collected in winter, directly at the producers’ retail outlets in southern and eastern Poland. The basic chemical composition was determined according to the Polish Standards, whereas the amino acid profiles of proteins from the cheeses were determined by ion-exchange chromatography. The result analysis revealed significant differences between the different varieties of cheese in terms of their water content, ranging from 32.2% to 42.1%, as well as protein content, which varied from 25.6% to 31.6%. Fat levels ranged between 22.2% and 24%, whereas total ash content amounted to 5.1-5.8%. The significantly highest salt content was found in unsmoked short-ripened cheeses. In all three cheese varieties, the total exogenous amino acid content was comparable, ranging from 46.17 g to 47.36 g/100 g protein, and that of endogenous amino acids varied from 52 g to 53 g/100 g protein. The biological value of proteins was determined by calculating to the chemical score (CS), as described by Mitchell and Block, and the essential amino acid index (EAAI), as described by Oser. A comparison of the results with the standard chicken egg white proteins showed that the limiting amino acids for all varieties of cheese were methionine and cysteine. On the other hand, a comparison with the FAO/WHO-suggested pattern of amino acid requirements (1991) for all age groups over 1 year of age showed that the limiting amino acids were methionine and cysteine in smoked and unsmoked short-ripened cheeses, and treonine in long-ripened cheeses. Considering the chemical indices, such as CS and EAAI, it may be concluded that the traditional rennet cheeses produced in southern and eastern Poland have a favourable amino acid composition of proteins and a high nutritive value..


Fisheries ◽  
2021 ◽  
Vol 2021 (4) ◽  
pp. 81-88
Author(s):  
Olga Mezenova ◽  
Dmitriy Pyanov ◽  
Svetlana Agafonova ◽  
Natalia Mezenova ◽  
V. Volkov

The perspective of the production of domestic compound feed for the development of industrial aquaculture in Russia is shown. Alternative sources of protein in mixed fodder for salmon and sturgeon have been investigated. The advantages of using protein hydrolysates instead of a part of fishmeal in compound feed are described. The advantages of protein hydrolysates from fish by-products are considered, the chemical composition and molecular fractional composition of sublimated protein hydrolysates obtained by enzymatic and thermal pathways from sardinella scales and ridges are studied. The presence in hydrolysates of 53.3 - 97.7% of low molecular weight peptides with a molecular weight of less than 10 kDa with a total protein content of 80.8-94.1% was established. Indicators of amino acid balance (scor) of hydrolyzates of scales and ridges of sardinella were calculated in relation to the established requirements for amino acids in salmonids. Indicators of amino acid balance (scor) of hydrolyzates of scales and ridges of sardinella were calculated in relation to the established requirements for amino acids in salmonids.It was found that the introduction of an enzymatically obtained hydrolyzate is more favorable for an increase in the content of limiting amino acids in mixed feed, and the use of sardinella scales for hydrolysis is more preferable than its ridges.


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